# Taxonomy of Data

#### Concept Acquisition

- Data is a collection of measurements of variables made on observation units. They can be organized in a data frame.
- Variables can be classified as Numerical or Categorical. Types of numerical variables include continuous and discrete variables. Types of categorical variables include ordinal and nominal.

#### Concept Application

- Identify the unit of observation in a written description of a study or in a given data frame.
- Identify the variables recorded on the observations based on a written description of a study or in a given data frame. Classify each one according to the taxonomy of data.
- Distinguish between a (tidy) data frame and other tabular displays.